Wheelchairs are well known transportation appliances enabling the infirm, disabled and unwell person to move about with greater mobility than otherwise. Essentially, wheelchairs are small, single person conveyances typified by a chair supported by two outer, large diameter drive wheels behind the center of gravity of the user, and with two smaller swivel mounted wheels or casters located toward the front. Motive power may be supplied by an attendant pushing the wheelchair, by the user's hands and arms applied to the drive wheels, or by an auxiliary power source.
While wheelchairs following many different designs have proliferated, there have been drawbacks heretofore that remain to be solved. In order to meet the needs and demands of the physically handicapped user, wheelchairs must be versatile and easily and readily adapted to accommodate the particular body shape and size of the user. Wheelchairs must also be versatile in adapting to both ambulatory and recreational travel, and they must be sufficiently rugged and durable to provide comfortable passage over uneven and irregular surfaces.
For instance, an unsolved need has arisen for shock and vibration attenuation control for providing extended opportunities and mobility to the user. Another unsolved need has been for a universal, adjustable chassis. Yet another unsolved need has been for a method of manufacture for a wheelchair chassis that enable a variety of preselected chassis specifications to be readily implemented during the manufacture of the chassis. Still one more unsolved need has been for a method of manufacture suitable for both specialized and volume production of a wheelchair chassis.